Guard for electric welders



March 25 1940 wjH. scHuLz 2,194,573

GUARD FOR ELECTRIC WELDERS Filed Aug. 27, 1938 Sheets-Sheet l fn0011170?, Wiiiz'amlc zzlz MMM w. H.lscHuLzvmuuu) :on ELECTRIC wwns IFiled Au'g. 27, r19;;58'l

2 Sheets-Sheet4 2 Willi-0227i.' Sczzlz 'Y 5y 1252427? Patented Mar. 26,1940 GUARD FOB. ELECTRIC WEIDERS william n. schulz, si. rsa1, assignerio' Donaldson Company, Inc., St. Paul, Minn., a corporation of MinnesotaApplication August 27, 1938, Serial No. 221,139

2Claims. (Cl.`2194) My invention provides an improved guard for electricWelders and, generally stated, consists of the novel devices,combinations of devices and arrangement of parts hereinafter describedand defined in the claims.

In the use of spot Welders and other electric weldlng'devices orapparatus, it is a well-known fact that the sparks produced will ily inall sorts of directions and'that` these sparks being m red lhot metalproduce very serious burning effects. 'To protect the operator or welderfrom these sparks theysometimes wear goggles and protecting aprons, butin the modern Welders there. is usually provided a shield in the natureof a frame having a transparent pane of glass or the like thereinsupported in'such position that the Welder back of the same can see thewelding operation and properly control the work. These Welders areusually employed in shops 2o where persons will pass or Workmen will benear the Welding operation and not protected by the shield. It isespecially to protect persons in the vicinity of the welding operation,other than the actual operator, that the improved device is provided.However, the improved shield does give additional vprotection even tothe operator. v

Welding machines of the modern type usually have a relatively fixedlower arm supporting a lower electrode and a relatively movable upperarm supporting the upper or movable electrode. In the operation of myinvention for welding machines of this character, the improved shield isapplied closely around the upper or movable Aelectrode and is preferablyprovided with alateral sight opening so aligned with the transparentpane of the shield that the operator can see the welding operation as ittakes place. Shields of the modern welders also usually have 4o areflector and a light bulb therein arranged to project a light beamthrough the sight opening of the shield and onto the electrodes forproper positioning and inspection of the work.

The various articles to be welded will have various form and it isimportant that the guard be capable of conforming always to the surfaceof the work and closely around the welding point or spot; and hence, theguard is made of elastic material such as rubber, but possibly of othermaterial such as leather or the like.

The improved guard is made bell-shaped and provided with a notch oropening in one side that is only large enough to permit good inspectionu of the electrodes and which will, therefore, intercept* all sparksexcept the few that may be projected out through the sight opening.

r'In the 'accompanying drawings, which illustrate a preferred form ofthe device applied to a Welding machine such as described, like char- 5acters indicate like parts throughout the several views.

Referring to the drawingsz l Fig. l is a perspective 'showing theimproved guard applied as above described;

Fig. 2 is a' front elevation of the parts shown inrlal; m

Fig. 3 is .an elevation showing the improved guard applied around theupper electrode;

Fig. 4 is 'a section taken on the line ,4-4 of '15" Fis. 3; Fig. 5 is aview lcorresponding to Fig. 3', but iilustrating a slightly modifiedform of the guard;

` and- Figs is a secties taken on the une s--s of Fig. 5.

The parts of the welding apparatus being of known` type may be brieflynoted as follows: 'I'he supporting pedestal Il is provided with thefixed lower arm Il equipped with a lowerj electrode l2. The relativelymovable upper arm I3 carries a shaft-like upper electrode Il that isequipsped with the depending removable electrode tip I The shield showninvolves a frame II with a transparent pane i1, a reflector Il, and alight bulb I9., I

The guard, the preferred form of which is illustrated in Figs. 1 to 4,inclusive, is a bellshaped structure shown as rectangular in horizontalsection. This bell-shaped guard 2h, which u i is preferably of rubber,is provided -in its front side with a notch 2i that aords a lightpassage so positioned that the operator looking through the pane orWindow il may see the tip of the o electrode I5, and the light beamprojected fromthe light bulb I9 will be projected through the opening 2|onto said electrode. In accordance with the present illustrations of theinvention.

the contracted neck portions of theelastic guards l' V2li and 20a aretelescopically applied around the electrode il Aand are adjustablyanchored thereto by frictional engagementtherewith brought about solelyby virtue of yielding tension exerted by'said neck portions on theelectrode. Itis, of 50 Y course, necessary to. the satisfactoryoperationI of the device that the elastic guards 20 and 20a engage theelectrode with sufficient tension toprevent accidental longitudinalshifting thereof from any desired adjusted portion, and, of course,

if this is to be accomplished in the manner illustrated and withoutresorting to auxiliary locking or clamping devices, the interiorportions of the elastic guards must be made slightly 5 smaller indiameter than the electrode to which they are to be applied so thatapplication of the neck portions to the electrode will requirestretching of said neck portions to the extent required to obtain thenecessary or 'desired degrec of frictional engagement with theelectrode.

project s guards will permit such distortion after contact with the workas is necessary to permit complete closing of the electrodes on to thework.

In Fig. 2 a band-like structure A, which has an irregular exterior, isshown as positioned on the lower electrode with the upper electrodepressed onto the same and the guard 20 deformed so as to closely fit theirregular surface of the said article A without interference withmovement of the electrodes into operative positions. Of course, theguard being of rubber or elastic material will resume its normal formwhen it is relieved from pressure.

In Figs. 5 and 6 the guard 20a is approximately sage is formed by anelongated perforation or hole 21a. In these views, Figs. 5 and 6, thelower electrode is indicated by the character lla, the upperelectrode'by the character lla, and the work being welded by thecharacter A.

hemispherical and a sight opening or like pas- 'I'he importance of thedevice illustrated is thought to be obvious and it is understood that itis capable of modifications Within the scope of the invention hereindisclosed and claimed. The guard is herein referred to as beingbell-shaped but that term is used in a liberal sense and not limited tothe exact form of the guard, either in axial or cross-section, as longas it has the housing effect of a bell-shaped device.

What I claim is:

1. In a welding machine having a pair of electrodes, one of which ismovable toward and from the other thereof, an elastic bell-shaped guardsurrounding one of the electrodes and having a reduced diameter neckportion telescopically applied over and anchored against accidentalmovement with respect to the enclosed electrode, and having its flaredelastic skirt portion terminating with its free edge in aplane closelyadjacent the plane of the free end of the enclosed electrode,` theelastic skirt of said guard being capable of great temporary deformationthroughout under engagementv with work of widely varying contourinterposed between the electrodes and without interfering with themovement of the electrodes into operative position.

2. 'I'he structure defined in claim l in which said reduced diameterneck' portion is also elastic and the normal diameter of said elasticneck portion of the guard is less than that vof the portion of theenclosed electrode to which it is applied, and in which said neckportion is stretched and under tension to contract, whereby the guard isanchored against accidental displacement solely by frictional engagementresulting from the elastic tension of said neck portion.

WILLIAM H. SCHULZ.

